Does it have a smell to it? Is it in the anal sac area? Has she had them cleaned out lately? My vet cleans Curly's about every 6-9 months, as that's about how often they get full for her. If they aren't cleaned often enough, they can rupture the sac and cause infection. It sounds like your girl has an infection and needs an anibiotic with the fluid/puss, and blood description. I'd take her to the vet soon.

**DISCLAIMER** - I am NOT a vet, only speaking from experience with my personal dog, and from what my vet has told me.

Even if it is benign, it's always easier to remove lumps while they are small and not infected. I would take her to your vet and ask if removal at this point would be appropriate since its starting to leak.